This invention pertains to the art of continuous casting, and more particularly to the inductive heating of endless edge dam blocks associated with an endless casting machines such as the casting belt of a continuous caster.
The invention is particularly applicable to inductive heaters used to preheat the edge dam blocks of a continuous belt caster or block caster which cast molten metal and will be described with particular reference thereto. However, it will be appreciated that the invention has broader applications and may be advantageously employed in other environments and applications. Where side or dam blocks are employed that could benefit from controlled heating.
In a belt caster for continuously casting molten metal, it is known that at least two endless flexible belts constructed of a durable material, such as carbon steel, are mounted on sets of pulleys such that the front surface of the two belts are in a facing relationship. A pair of dam blocks are located at the outer edges of at least one of the endless belt front surfaces so that the dam blocks and endless belts form a casting region. Molten metal is delivered to the casting region such that the molten metal is cast into metal of varying width and gauge depending upon the dimensions of the casting region. The casting region consists of a casting zone where metal is received in a molten form, and a cooling zone where the metal is caused to solidify.
In a block casting machine typically including a caterpillar mold of articulated mold blocks, the mold cavity is also defined by opposed pairs of edge dam blocks.
The introduction of heat from the molten metal to the casting belts, mold blocks and dam blocks can cause the casting region to expand. The molten metal heating applied to the belts is often unregulated and uneven. Such unregulated application of heat causes the belts to expand in an uneven, non-regulated manner and results in distortions of the metal being cast due to distortions in the casting and cooling zone. It is a particular problem addressed by the subject invention that the dam blocks themselves may be of a temperature during the casting region to cause an undesirable heat loss from the casting region.
U.S. Pat. No. 5,133,402 discloses a system for inductively heating the first and second endless belts prior to introduction of the molten metal into the casting region to minimize heat loss from the casting due to engagement with the belts themselves. Accordingly, in this prior art system a portion of the casting region is preheated, but the problems still remain that the dam blocks will oftentimes be the cause of undesirable heat loss from the casting operation.
The present invention contemplates a new and improved apparatus and method which overcomes the above-referred to problems and others. The apparatus comprises a new continuous casting device with a heating system for preheating the dam blocks which is simple in design, conveniently sized for the physical space required to employ it, economical to manufacture, adaptable to a plurality of dimensional characteristics, durable, and which provide an improved uniform transfer of heat to dam blocks in a substantially instantaneous manner over a limited physical area such that the casting operation is more predictable and controllable to in turn provide a better uniform casting of the metal.